Engineering Project Case Studies | Erdman Anthony

Superstructure Replacement Design

This project involved preliminary engineering, final design, and construction consultation services for the replacement of the superstructure on a 40-foot-long single-span steel-beam bridge carrying Babcock Boulevard over Girtys Run (SR 4009/A11).

The project was originally scoped as a bridge replacement; however, after consulting with PennDOT , District 11-0 and and conducting concrete testing of the existing abutments, the design team determined that it would be possible to retain and repair them, replacing only the superstructure. The scope of work included:

• structural design
• minor approach-roadway design
• traffic control using phased construction and a brief detour for superstructure placement
• hydrologic and hydraulic analysis
• coordination with the owners of overhead and underground utilities
• Phase 1 Environmental Site Assessment
• constructability reviews
• field survey
• public involvement

Structural design included repairs to the existing concrete abutments and the replacement of an existing gabion-type wingwall with a cantilever-type wingwall using precast-concrete components.

The constructability review included an evaluation of the crane size/placement and of the delivery truck location to determine potential impacts to existing utilities and adjacent businesses during construction.

Accelerated bridge construction (ABC) techniques used for this project included construction of four prefabricated superstructure modules. This enabled the bridge to be constructed using a five-day detour, minimizing disruption to traffic along the heavily traveled corridor and reducing impacts to businesses close to the corners of the bridge.

Bernard Zimmovan, PE
Bernard Zimmovan, PE
 (412) 494-0505 x 5102